106 Recent Ornithological Publications. 
who have taken descriptions from the types of the Leyden col¬ 
lection is well known to be considerable. Le Vaillant, Temminck, 
Kuhl, G. Cuvier, Valenciennes, Bonaparte, Boie, S. Muller, and 
Hartlaub are those mentioned by Dr. Schlegel, to whom we may 
add—last, but not least—Dr. Schlegel himself. The Leyden col¬ 
lection is likewise remarkable for the number of specimens it 
contains which have been obtained by the travelling naturalists 
employed by the Dutch Government in their Indian possessions 
and the neighbouring islands, and of which the exact localities 
(so often wanting in most other collections) have been carefully 
preserved. These two points greatly increase the value of 
Dr. Schlegeks work, particularly as regards the additions it is 
likely to make to our knowledge of the geographical distribu¬ 
tion of species. 
Dr. Schlegel commences his catalogue with the genus Buce- 
ros } and then passes on to the Accipitres, of which he succes¬ 
sively handles what he terms the Falcones } Aquilce , Astures, 
Asturince , and Buteones. We cannot be expected to agree en¬ 
tirely with Dr. Schlegel in certain well-known points, in which 
he holds views certainly not in accordance with those of the great 
body of modern naturalists. With respect to his reduction of 
representative species into what he now calls “ conspecies” with 
three names to each, we shall only remark that we fear it is 
impossible in many cases to draw the line between species and 
conspecies, and that this method only removes the great ques¬ 
tion “ what is a species ? ” to another spot, instead of solving 
it. Neither can we be expected to agree with Dr. SchlegePs 
somewhat exaggerated extension of generic groups. It may be 
very true that matters have been pushed to rather an extreme 
in the opposite direction of late years. But if Serpentarius and 
Thrasaetus be united to Astur , Gypaetus to Haliaetus , and Po- 
lyboroides to Nisus , we shall be compelled to alter our whole 
system of modern nomenclature, and if uniformity is requisite, 
to cast, in some cases, hundreds of species into the same 
genera. We cannot accede to so great a retrogression. But 
these and some other minor points which seem open to criticism, 
such as Dr. SchlegePs adoption of antiquated pre-Linnean 
names in some instances, do not detract from the value of the 
